KANSAS CITY, Mo. — Missouri voters said yes to legalizing marijuana on Tuesday, but one Kansas City area police department is already raising a red flag.

The unofficial vote on Amendment 3 was closer than what experts predicted, but marijuana legalization garnered about 53% support Tuesday.

“I think Missouri today is a better place based on the fact that we actually have legalized recreational marijuana,” Kansas City Mayor Quinton Lucas said.

Missouri is now one of 21 states, as well as Washington D.C., to legalize marijuana in the United States.

The new amendment changes the state constitution to allow those 21 and older to possess up to 3 ounces of marijuana and have up to six flowering plants, six clones and six seedlings.

The Missouri Department of Health previously said the earliest people will be able to buy recreational marijuana in Missouri is February, but across the state line in Kansas, police are already concerned.

“I think so,” KCK Police Chief Karl Oakman said when asked if he think marijuana legalization will make officers’ jobs harder. “I think we’re going to have an increase in some traffic-related issues … It’s legal in Missouri, but it’s still illegal in Kansas.”

Kansas state lawmakers have failed to approve a medical marijuana bill multiple times. It’s one of only three states that has not implemented any kind of public-use marijuana program.

Oakman said education around driving while high must be a top priority for Missouri leaders.

Lucas said it’s time for Kansas to follow in Missouri’s footsteps and legalize marijuana.

Regardless, employers will still have the final say on whether their employees can use marijuana. The new amendment does not prevent employers from enforcing their drug and alcohol-free workplace policies.

The AFGE Local 910 union president also told FOX4 this has no impact on federal employees because there is still a federal ban on the drug.

The amendment will, however, erase past marijuana-related convictions for nonviolent offenders and those whose conviction didn’t include selling to minors or driving while high.

“I think that this will reduce substantial harms, particularly those for minority communities who have been arrested at disproportionate rates for years and years,” Lucas said. “I think this is good.”